ALPINE, Utah (AP) – U.S. Rep. Jason Chaffetz’s ascent to national prominence leading a House oversight committee was rooted largely in his embrace of the spotlight and willingness to take on confrontations.

But the 50-year-old Utah Republican said this week that he’s stepping aside from Congress next month during the prime of his career and just as his committee was poised to investigate President Donald Trump’s firing of the FBI director.

It’s a probe that could have allowed Chaffetz to prove he was sincere when he promised constituents at a raucous February town hall that his job was “not to be a cheerleader for the president.”

Some political analysts in Utah have suggested the former public relations specialist is making a political chess move to avoid constant attacks about his perceived lack of zeal in investigating Trump and the difficult position those investigations would put him in with his own party, especially if he runs for Utah governor in 2020.

Chaffetz acknowledged the speculation but insisted to reporters that “the overwhelming driving force” of his resignation was a desire to spend more time with family as he realized he was in a mid-life crisis.

“A lot of people will never believe that,” he said. “But that is the truth.”

Jacob Carlson, a 27-year-old college student in Chaffetz’s district who has voted for Republicans and Democrats but leans Republican, said he viewed Chaffetz as a decent politician but was disappointed he did not investigate Trump more vigorously.

“One of my biggest complaints with politics in general is that people play favorites depending on their party,” said Carlson, of Provo. “I hope whoever takes his place will do better than he did at a proper investigation of all that garbage with ties to Russia.”

Chaffetz’s abrupt exit upends the latest of the Republican-controlled congressional investigations into Trump and also marks a sudden halt to Chaffetz’s decade-long climb to power.

Born in California, Chaffetz was raised in Colorado and used to be a Democrat. His father’s first wife later married former Massachusetts governor Michael Dukakis.

As a college football kicker at Mormon-owned Brigham Young University in Utah, Chaffetz stumped for Dukakis during his 1988 presidential campaign. He later converted to Mormonism and became a Republican after meeting President Ronald Reagan when Reagan visited the marketing company where Chaffetz worked.

Chaffetz became a campaign manager and chief of staff to former Utah Gov. Jon Huntsman, Jr. but they had a falling out in 2012 when Chaffetz endorsed Mitt Romney for president over Huntsman.

Chaffetz won his congressional seat in 2008 by defeating a conservative incumbent with deep ties to Utah’s political establishment, Chris Cannon, after accusing him of being soft on immigration.

Chaffetz breezed through his re-election battles and ascended to chairmanship of the House Oversight and Government Reform Committee in 2015, a position that set him on a fast track to national prominence.

He tangled with the Secret Service while leading a probe into security lapses at the White House and on presidential trips. The Secret Service Director Joseph P. Clancy eventually apologized publicly to Chaffetz because dozens of his agents looked into Chaffetz’s 2003 job application with the agency to dig up dirt on the congressman.

Chaffetz’ dogged investigation of Democrat Hillary Clinton’s emails from his committee chair over the last several years earned him acclaim from his party and helped him carve out a larger platform with frequent appearances on cable TV.

But Trump’s victory complicated Chaffetz’ life.

He rescinded his endorsement of Trump last year after recordings surfaced of the reality show star bragging about groping women, with Chaffetz saying he couldn’t look his teenage daughter in the eye and support Trump. He later re-endorsed Trump shortly before the FBI announced it was reviving its investigation into Clinton’s emails.

After Trump won, liberals hammered him for not going after Trump’s administration with nearly the vigor used against Democrats.

Chaffetz finally appeared ready ready to dig into Trump’s dealings, vowing Tuesday to get the memos FBI Director James Comey wrote about his meeting with Trump in which the president allegedly asked him to shut down the FBI investigation into ousted National Security Adviser Michael Flynn.

Two days later, he announced he will resign June 30 – saying he wanted to leave behind countless nights of fast food burgers and sleeping on his office cot in Washington to be reunited with his family in an upscale Salt Lake City suburb.

He said one of his colleagues can handle the Trump investigation, adding that his committee must first find out from the U.S. Department of Justice if documents exist to verify allegations of Trump’s tampering with the FBI review of his campaign’s ties to Russia.

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.